Rock drilling apparatus



Oct. 27, 1953 J. c. CURTIS ROCK DRILLING APPARATUS 4 Sheets-Sheet 1 Filed March 22, 1952 INVENTOR: JOHN C. CURTIS BY W I I ATTORNEY J. C. CURTIS ROCK DRILLING APPARATUS Oct. 27, 1953 4 Sheets-Sheet 2 Filed March 22, 1952 III/7 INVENTOR: JOHN C. CURTIS ATTORNEY Oct. 27, 1953 c, -n5 2,657,017

ROCK DRILLING APPARATUS Filed March 22, 1952 4 Sheets-Sheet I5 INVENTOR: JOHN C. CuR'rls MM/Z.

ATTORNEY Oct. 27, 1953 c, -n5 2,657,017

ROCK DRILLING APPARATUS Filed March 22, 1952 4 Sheets-Sheet 4 FIG. 7.

INVENTOR: JOHN C. CURTIS 4/' BY 2 Z 2 m a,

ATTORNEY -tanceabove the-base.

Patented Oct. 27, 1953 ROCK. DRILLING APPARATUS John 0. Curtis,

Newport, N. H., assignor to Joy Manufacturing Company, Pittsburgh, Pa., a corporation of Pennsylvania Application March 22, 1952, Serial No. 278,050

20 Claims. 1

Thisinvention relates todrilling apparatus and. more particularly to an adjustable mounting structure fora hammer rock drill.

In quarries, metal mines or the like, it is frequently desirable to drill blast holes of substantial depth in the rock, and while such holes are generally horizontal, it is also desirable, under certain conditions, to drill holes which extend generally vertically.

The drilling of such blast holes is usually accomplished by hammer rock drills of the mounted type and certain known types of drills are particularly adapted for use in the horizontal drilling of relatively deep toe holes in a working face such as encountered in deep quarry work or in large headings of limestone mines, and other known types are adapted for drilling blast holes in metal mines. Other known types of drilling apparatus are designed particularly for drilling vertical holes.

The present invention contemplates improve ments over suchknown typesof drilling apparatus in that an improved adjustable supporting structure is provided whereby a drill support or guide frame may-be quickly adjusted either 1a;t-

erally or vertically through the desired range, and may be firmly held in adjusted position with respect to the work. The drilling apparatus of the present invention may embody a mobile base on which a support is swivelled to turn about a vertical axis and the swivelledsupport carries at its Opposite sides relatively adjustable, oppositely extending boom frames or jibs on which an elongated guiding frame or a support for ,a drilling tool is mounted. The boom frames or jibs may be swung independently in vertical planes about their respective pivots to effect tilt- ;ing of the drill support or guiding frame in vertical planes, and connections are provided between the outer ends of the .boom frames and the support orguiding frame for permitting a limited range of lateral adjustment, of the support or guiding frame supplemental to the turning adjustment of the swivelled support. Further, to obtain flexibility in adjustment, either or both of the frames maybe extensible, and the boom "frames, may be concurrently or independently swung about their pivots to move the support or guiding framein vertical planes through a wide rangeof'horizontal andtilted positions including horizontal and-tilted positions a substantial dis- The connections between the outer ends of the support or guiding frame and the boom frames'may embody swivels and at least one of the connections may have-longitudinal sliding engagement with the support or guiding frame to compensate for the swinging movement of the boom frame with respect to the support or frame. The boom frames may also be positioned to locate the drill support to support the guide framein vertical positions.

It isaccordingly a primary object of the pres, ent invention to provide an improved rock drilling apparatus having an improved adjustable mounting structure for the hammer rock drill whereby the latter may be adjusted through a relatively wide range in both horizontal and vertical planes. Another object is to provide an improved adjustable mounting structure for a support or guiding frame for a hammer drilling tool and embodying oppositely extending, relatively adjustable, swingable supports connected to the tool support or guiding frame at points spaced longitudinally of the latter for elevating and tilting the drill support or guiding frame in vertical planes. Yet another object is to provide an improved adjustable supporting structure mounted to turn about a vertical axis and embodying oppositely extending, independently adjustable, swingable supports for a drill support or guiding frame whereby the latter may be adjusted horizontally .and tilted endwise in either direction in vertical planes. A further object is to provide .an improved drill mounting structure including a drill support or guide frame and oppositely extending, independently swing-able, elongated boom frames having connection with the drill support or guide frame at points spaced longitudinally of the latter and relatively swingable about their pivots to. tilt the drill support or guiding frame either upwardly or downwardly. in vertical planes. Yet another object is to provide an improved adjustable drill mounting embodying adjustable, pivoted, boomlike supports which may be adjusted about their pivots to move the drill support or guiding frame in vertical planes through a wide range of horizontal positions, and fortilting the drill support or guiding frame in any such position. Still anotherobject is to provide in such a drill mounting, improved adjustable connections between the boom frames and the drill support or guiding frame for permitting an additional lateral adjustment of the guiding framesupplemental to' the adjustment of the swivelled support thereby toprovide a rela tively wide range of angular adjustment of the drill support or guiding frame in horizontal planes. Still another object is to provide an improved adjustable mounting structure embodying oppositely extending, pivoted boom frames having pivotal connection with the drill support or guiding frame, and also having a limited sliding commotion between the drill support or guide frame and one of the boom frames, whereby the boom frames may be independently adjusted about their pivots to effect elevation and endwise tilting of the drill support or guiding frame. A still further object isto provide an improved boom frame mounting for a hammer rock drill wherein at least one of the boom frames is extensible thereby to increase the range of adjustment of the drill support or guide frame with respect to the work. Still another object is to provide improved fluid actuated adjusting means for the boom frames whereby the same may be swung about their pivots or extended under the action I of fluid under pressure and embodying improved means for trapping the fluid in the adjusting devices for locking the boom frames in adjusted position. These and other objects and advantages of the invention will, however, hereinafter more fully appear.

This application is a continuation-in-part of my copending application, Serial No. 143,550, filed February 10, 1950, now abandoned.

In the accompanying drawings there are shown for purposes of illustration several forms which the invention may assume in practice.

In these drawings:

Fig. 1 is a plan view of a drilling apparatus constructed in accordance with a preferred illustrative embodiment of the invention.

Fig. 2 is a side elevational View of the drilling apparatus, shown in Fig. 1.

Fig. 3 is an enlarged central longitudinally extending vertical section taken substantially on line 3-3 of Fig. l, with parts shown in full to facilitate illustration.

Fig. 4 is an enlarged vertical section taken on the planes of line 4-4 of Fig. 2, showing the movement permitting or sliding connection between the rear boom frame and the drill guiding frame. a

Fig. 5 is a fragmentary side elevational view showing an adjustable drill mounting of a modifled design. 7 r

Fig. 6 is an enlarged section .takenon the planes of line 66 of Fig. 5, illustrating one of the extendable booms of the modification shown in Fig. 5.

Fig. '7 is an end elevational view of a drill support of anothermodified design.

Fig. 8 is a plan view of the modified construction shown in Fig. '7.

In the illustrative construction shown in Figs. 'l to 4 inclusive of the drawings, a mobile base I has a frame 2 mounted on pairs of front and rear, rubber-tired wheels 3 and 4. Conventional The lower portion of the swivelled support H has a conical flared portion [2 having an internal conical surface 13 engageable with an external conical surface M formed on the lower portion of the pedestal. The support II has limited axial adjustment with respect to the pedestal, and a screw and nut device 15 is provided for moving the support H downwardly relative to the pedestal to bring the conical surfaces into frictional locking engagement to lock the swivelled support H against turning movement. This screw and nut device comprises a vertical screw shaft [6 arranged centrally in the hollow pedestal and threadedly secured at I! to the bottom portion of the pedestal, as shown in Fig. 3. A rotatable nut 18 provided with a handle I9 engages the upper threaded portion of the screw shaft and rests against the top of the support I I and this nut may be rotated to tighten or loosen the frictional look. This type of swivel support mounting and the frictional lock arrangement are fully disclosed in my copending application, Serial No. 563,579, filed November '15, 1944, now matured into Patent No. 2,500,931, granted March 21, 1950. i

The swivelled" support H has forwardly and rearwardly projecting parallel vertical side plates or flanges 20 and mounted outside these flanges and pivotally connected at 2| to the upper portions thereof is a pair of elongated, oppositely extending, boom frames or jibs 22 and 23 which extend forwardly and rearwardly with respect to the base. Pivotally connected at 24 between the lower portions of the parallel flanges 2i and the boom frames, below the latter, are oppositely extending fluid cylinder and piston devices 25 and 26 and these devices are pivotally connected at 21 at their outer ends to the boom frames 22 and 23 respectively. Each of these cylinder and piston devices includes, as shown in Fig. 3, a fluid cylinder .28 having lugs 29 at its outer end engaging a pivot pin 30 carried by lugs 3| integral with the boom frame. Contained in the cylinder is a piston 32 having its piston rod 33 extending outwardly through the inner cylinder head and having lugs 34 pivotally engaging a pivot pin 35 carried by the parallel support plates 20. Each of the boom frames, in this instance, carries a fluid tank 36 and a conventional hand pump having a hand lever 31 whereby fluid under pressure may be suppliedthrough a flexible conduit 38 to the I outer end of the fluid cylinder. Associated with fluid motors 5 each having a control valve 6,

are operatively connected to the wheels with one motor individual to each pair of side wheels, whereby the side wheels may be independently driven to effect propulsion and steering of the base in a well-known manner. The base frame carries a horizontal top plate I, and secured, as by bolts 8, to this plate at one side of the base is a circular bottom flange 9 integral with a vertical columnlike, hollow support or. pedestal l0 (see Fig. 3). This pedestal is of cylindrical tubular form open at its top, and has swivelled thereon a support H which is turnable about a vertical axis relative to the base. Evidently, the pedestal may be located in other positions on the top plate and, if desired, the pedestal may be located at the center or at one end of the base.

the pump is a conventional vent valve having a hand lever. 39 whereby the fluid may be trapped.

in the cylinders or the cylinders may be vented. Thus, when fluid under pressure is supplied to the outer ends of the cylinders the boom frames 22 and 23 may be swung upwardly in vertical planes about their pivots and when fluid is vented from the cylinders the boom frames may swing downwardly at a controlled rate. When fluid is trapped in the cylinders the boom frames may be locked in adjusted position.

inders.

Supported by the front and rear boom frames or jibs22; and 23 at their outer remote ends is These boom frames, their associated cylinder and pisan elongated horizontal: drill supportioriguiding frame on which a conventional fluid operated hammervrock. drilling tool 41! is-guidedfor movement, back and forth longitudinally therealong. This drilling 13001 includes a conventional hammer -:motor for :percussively actuating an elonated drill steel 42' which carries a drill bit 43 at its forward end, in a well-known manner. Mounted at the front end of the guiding frame is a conventional centra-lizer 44nfor guiding the drill \bit'during-starting-of the drill hole. A fluid operated feeding motor 45;h'aving:a control valve 46 is carried at the front end; of theguiding frame :below the latter and is opera-tively connected to thedrilling tool .for feeding the latter back and forth along the guide frame. This motor operated feeding means may begenerally similar to that disclosed in my Patent No. 2338;625,datedJanuary-a, 1944. Theouter end of the front boom frame or jib 2- 2. carries-atransverser-igid arm or horizontal-bar, and asaddle 48 :is adjustably clamped at 49 to this arm, and maybe lo'catedin different lateral positionslalong the-arm. This" saddle has a usual .socketfor receiving' a swivel plate or cone :50 secured to a bracket 51 adjustably clamped to the bottom of the guiding frame. This bracket has'screws 52 for rigidly securing the bracket to the guide frame. Thevreariboom frame or jib 2-3 carries at its outer end a rigid transverse arm or horizontal bar 54 which is somewhat longer than the horizontalbar 4l, as shown tin-Fig. 1. Asaddle 55 is adjustably clamped at '56 to the horizontal bar '54, and thissaddle may be adjusted into different lateral *positionsalong the length of the arm 54 and rigidlyclamped in adjusted position. The saddle55 has ausualsocketifor receiving a swivel plate or cone 51 secured to a bracket 58 having slidin connection at 59 with thebottomsof the guiding frame. Screws 60 carried by the bracket (Fig. 4) are engageable with the :guiding frame for rigidly securing the bracketto .the guiding frame when the latter isinits adjustedposition.

-By loosening the clampsof ithe, saddles=48 and 55-and by sliding the saddles, laterally along the arms l'l and '54 the guidingframe Alhmay be adjusted laterally into different angular. ,positions relaitve to the boom frames and by tightening the saddle clamps the guidingframe-may be rigidly securedinsposition. Upon looseningofthe frictionlock l3, l-4, the swivelledrsupport, it may .be turned about its vertical axis toadjust .the boom frames 22 and Ziand. theguiding frame 40 carried thereby inihorizontal planes with -,re-

spect to-themobile base, (and when the friction lock is tightened the swivelled support istflrmly secured in position. The leverssl of the hand pumps may be independently operatedtopump fluid, desirably a liquid under pressure, to the cylinders of the cylinder-and "piston devices 25 a2 "and-26 to swingwthe boom frames or jibs 22 and .23 independently in vertical planes about their pivots relative to the swivelled support 11 toitilt the guiding frame 40 either upwardly ordownwardly in anendwise direction in vertical planes relative to theamobile :base. The boomeframes may be tconcurrentlyadjusted to move the guidrin frame 40 in vertical planes through a wide range of horizontal positions, including positions a substantial distance above the base. When the guiding frame is'inlts lowermost horizontal'posi tion the drill is located close to the ground surface. As the guidingframe 40 is adjusted bythe' independently swingable'boomframes thebracket 58 which connects the rear boom frame with the guiding ,zframe may slide longitudinally along guiding frame tocompensate for thevaryingdistances between the remote ends of the boom frames as the latter are independently adjusted. Different laterally adjusted positions of the-guiding frame are indicated in dotted linesin Fig. 1,, while different tilted positions of theguiding frame are indicated in dotted lines in Figw2. During adjustment of the drill guiding frame-4,0 the saddle clamps 4'9 and 5G and the screws--50 of the rear sliding bracket 58 are loosened to permit free relative movement between the boom frames and the guiding frame, and after adjustment has been made th saddle clamps and the rear slidin bracket are firmly secured inposition to'hold the guiding frame rigid.

In the modification shown in :FigS. 5 and 6, a frame-6,5 of any suitable base, such as themobile base of the preferred embodiment above described, carries a support I l on which elongated, oppositely extending, .swingable boom frames or jibs 22 and, 23' arepivotally mounted tocswing in. vertical planes. Fluid, cylinders 2-5 and 26', in this instance desirably of the double acting type, serve to swing the boom frames in vertical planes about their pivots, and when fluid is trappedwithinvthese cylinders, the boom frames may be firmly locked in. adjusted position. One or both of these boom frames may, in this improved-construction, abeextensible, and as shown in Fig. 6, the front boom frame 22' comprises a reciprocable cylinder 66 of the ldouble acting type containing a piston 61 having its piston rod 68 extending axially through a tubular element 69 which, in turn, extends forwardly through the inner packed head 10 of the cylinder; This tobular element 69 is secured at H toa transverse plate element 120i the front boom frame. A cylindrical tubularelement 1,3 surrounds the piston rod and aportion of the fluid cylinder, in themanner illustrated, and this tubular element is secured, as by welding, at itsinner-end tothe transverse element 12. The reciprocable boom cylinder 6611s desirably splined against rotation with respect to the tubular element 1:3. ,A conduit 14 is connected through a passage 15. with the-interior of the tubular element 69 whichcommunicates with the inner end of the-bore of the cylinder 66, and a secondlfluid conduit Isis-connected at 11 to the piston rod 68 which :hasan axial passageway extending therethrough which communicates with the outer end of the bore of the cylinder fifi. Thus, fluid under pressure may be supplied through one of the conduits to the cylinder boreat one side or the other of the piston 61 while the boreattheiother side-of the-piston is connected to exhaust. By trapping fluid within the cylinder-65 at opposite-sides of the piston the extensible boom frame maybelocked in adjusted position. .Any conventional control valve means connected to a suitableiluid source may control the supply and exhaust for the fluid cylinder 65;

A suppcrt ilf is secured, as bya split clamp :81, to-the eutenend portion of thefluid cylinder "65 .and thissupport carries asplit saddle clampB'Z which'engages a horizontal cross bar 83 for securingthe latter firmly in position on the support $10. This'cross bar is rigidly securedat its ends :toside plates 84 which are in -t-urnsecured arigidly to the ends of a parallel crossbar 385. Clampedes :by a split saddle clamp 8 5, to the cross bar -85 is a saddle 48' which isra dj-ustably clampedito the bottom of the. guidingframe lzfl 7 The rear boom frame 23 carries a similar support 80 for similar parallel cross bars 83 and 85 and is likewise connected by a saddle 55 to the guiding frame although in this instance the sad dle has a longitudinal sliding conection with the guide frame. It will thus be seen that when fluid under pressure is suitably supplied to the cylinder 66 the latter may be extended to move the drill support or guide frame Ml into its foremost position, as shown in dotted lines in Fig. 5, and during such adjustment of the guide frame the latter slides longitudinally relative to the saddle mounting of the rear boom frame 23'. In the event that both boom frames 22 and 23" are made extensible, the saddle mountings 53 and 55' may be suitably clamped to the guide frame so that when either saddle is clamped to the guide frame the other is released to permit longitudinal sliding adjustment of the guide frame with respect thereto. Otherwise, this embodiment is similar to that above described.

In the modification shown in Figs. '7 and 8, a mobile base i has a forwardly projecting frame 90, on which a support Eli, similar to the support H, is mounted. This support, if desired, may be swivelled to turn about a vertical axis in the manner of the support I l of the preferred embodiment, as shown in Fig. 3. Pivotally mounted on the support 9i and projecting laterally in opposite directions from the sides thereof across the front end of the base are the boom frames 2?. and 23' which have double acting fluid swing cylinders 25 and 2?, as in the embodiment shown in Fig. 5. The boom frames may be either rigid or extensible as desired. In this modified construction, the elongated horizontal drill support or guide frame it has been removed and in its place, supported by the clamps 86 of the saddle mountings on the cross bars 83, is a horizontal cross bar or transverse support 92 located high above the base. Attached, as by a split saddle clamp 93, to the cross bar 92 intermediate the saddle clamp 86 is a vertical drill guide frame 9% on which the hammer rock drilling tool oi is guided for back and forth vertical movement to effect drilling of vertical holes in the'ground. The elevation of the horizontal cross bar 92 may be varied by loosening either or both of the saddle clamps 85 and swinging or extending the boom frames 22' and 23' to effect raising or lowering of the cross bar 92, and, under certain conditions, the cross, bar may be tilted with respect to'the horizontal simply by adjusting one boom. frame with respect to the other.

' In this particular construction, the drill guide frame has a usual swivel plate 95, similar to the swivel plates 59 and 5'2, clamped in the saddle mounting 93, to permit a variation in the angular position of the drill guide frame with respect to the horizontal cross bar. Evidently, the length of the horizontal cross bar 92 may be varied as desired. V As a result of this invention, an improved adjustable supporting structure is provided for a hammer drilling tool whereby the latter may quickly and expeditiously be adjusted through a relatively wide range of drilling positions with respect to the work. The oppositely extending, swingable supports for the drill support or guide frame enable adjustment of the drilling tool into different positions including positions to drill work or in limestone mines. Further, the swing- 8 able drill supports may be adjusted to support a drilling tool in vertical drilling position. By the provision of the elongated guiding frame or support for the hammer drilling tool and the pivoted boom frames for supporting the guiding frame or support the latter may be adjusted both in horizontal and vertical planes thereby to locate the drilling tool in different drilling positions with respect to the face of the work; The elongated guiding frame provides a relatively long range of feed for the drilling tool thereby enabling the drilling of relatively deep holes without the necessity of frequent steel changes. The fluid operated, oppositely extending, swingable boom frames or libs on which the drill support is mounted enable vertical adjustment of the drill support through a relatively wide range, and the swivelled support, together with the supplemental laterally adjustable connections between the guiding frame and the jibs, provide for a relatively wide range of lateral adjustment. By the provision of the extensible boom framethe drill support may be adjusted through a relatively Wide range either longitudinally or vertically, The drilling apparatus is not only relatively rugged, compact and simple in design but is also readily mobile, well adapted for its intended purpose. These and other advantages of the invention will be clearly apparent to those skilled in the art. While there are in this application several forms which the invention may assume in practive, it will be understood that these forms of the same are shown for purposes of illustration and that the invention may be further modified and embodied in various other forms without departing rom its spirit or the scope of the appended claims. a

What I claim as new and desire to secure by Letters Patent is:

'1. A drilling apparatus comprising, in combination, a mounting structure, a support carried by said mounting structure, oppositely extending boom frames pivotally mounted on said support to swing in vertical planes with respect thereto and projecting laterally in opposite directions with respect to said support, an elongated drill support carried by said boom frames, means for mounting said drill support on the outer ends of said boom frames including a connection providing for relative movement between one of said boom frames and said drill support during adjustment of the latter, and adjusting devices connected between said first support and said boom frames respectively for swinging the latter about their pivots to vary the drill supporting position of said drill support withrespect to said mountboom frames one relative to the other to 'vary.

their relative elevations thereby to effect tilting of said drill support with respect to said mounting structure. a

4. A drilling'apparatus as set forth in claim 1 wherein said first support is mounted on said mounting structure to turn about a vertical axis for varyingthe-angularposition of'said drillsupport in horizontal planes: with respect to said ing' said boom frames about their respective pivots, and-means for mountingsaiddrill support on the outer ends of said boom frames including a movable connection between one boom frame and said drill support to permit relative movement between said drill support and said one boom frame during swinging of the latter;

6. A drilling apparatus as set forth inclaim wherein said movable connection includes a slide between said one boom frame and said drill support permitting sliding movement longitudi- -nally of said drill support during swinging of said" one-boom frame.

71 In a drilling apparatus, the combination comprising a base, a support swivelled on said baseto turn about a vertical axis, oppositely extending boom frames pivotally mounted on said swivelled support to swing in vertical planes with respect thereto, an elongated horizontal drill guiding frame carried by said boom frames:

andprovidingaplongitudinal guideway for a drilling tool and along which a drilling tool is adapted to be guided. for movement lengthwise of said frame toward and from the work, means for mounting said guiding frame on said remote ends of said boom frames and including a connection between one boom frame and said guiding frame permitting relative movement therebetween during swinging of said one boom frame, and adjusting devices connected between said support and said boom frames respectively for independently swinging said boom frames about their respective pivots to tilt said guiding frame in vertical planes with respect to said base.

8. A drilling apparatus as set forth in claim 7 wherein said mounting means between said boom frames and said guiding frame includes a longitudinal sliding connection between said one boom frame and said guiding frame.

9. In a drilling apparatus, the combination comprising a base, a support swivelled on said base to turn about a vertical axis, oppositely extending boom frames pivotally mounted on said swivelled support to swing in vertical planes with respect thereto, an elongated horizontal drill guiding frame, means for mounting said guiding frame on the outer remote ends of said boom frames and including a swivelled connection between each boom frame and said guiding frame with the swivel axes disposed parallel with the pivotal axes of said boom frames, the connection between one of said boom frames and said guiding frame also permitting relative movement longitudinally of said guiding frame during swinging of said one boom frame, and adjusting devices connected between said support and said boom frames respectively for independently swinging said boom frames about their respective pivots thereby to tilt said guiding frame in vertical planes with respect to said base.

10. In a drilling apparatus, the combination comprising a base, a support swivelled on said base to turn about a vertical axis, oppositely extending boom frames pivotally mounted on said swivelled support to swing in vertical planes with respect thereto, an elongated horizontal drill also including laterally adjustable connections .between said boom frames: and said guiding frame for permitting. lateral adjustment of said guiding frame relative to saidboom frames, and adjusting devices connected between said support and said. boom frames respectively for independently swinging said boom frames about their respective pivots thereby to tilt said guiding; frame in. vertical planes with respect to said base.

11. A drilling apparatus as set forth in claim 10' wherein: said: connection between one of said boom frames and said guiding frame comprises a longitudinally sliding connection which permits sliding movement. longitudinally of: said guiding frameduring swinging of said one boom frame about its pivot and said mounting means also: including a longitudinally fixed connection between said. other'boom frame and said guiding frame.

l2. In a drilling apparatus, the combination comprising: abase; an elongated horizontal guiding frame along which a drilling tool is adapted tobefgui'ded toward and from the work, andan adjustable. mounting structure for said guiding frametswivelled on said basetoturn about a vertical axisandinclhdihg oppositely extending supports either oneadjustable relative to the other and engaging said guiding frame at points spaced longitudinally of the latter, means for mounting said guiding frame on the remote ends of said adjustable supports including a connection between one of said supports and said guiding frame permitting relative movement therebetween, and adjusting means for said supports for independently adjusting the latter in any swivelled position of said mounting structure with respect to said base.

13. A drilling apparatus as set forth in claim 12 wherein said connection between said one of said supports and said guiding frame comprises a longitudinal sliding connection permitting sliding movement longitudinally of said guiding frame during adjustment of said one support.

14. A drilling apparatus as set forth in claim 12 wherein the mounting means between said guiding frame and said supports also provides for limited lateral adjustment of said guiding frame relative to said supports.

15. In a drilling apparatus, the combination comprising a base, a support mounted. on said base, a pair of oppositely extending boom frames pivotally mounted on said support to swing in vertical planes with respect thereto and projecting laterally from opposite sides of said support, an elongated horizontal drill guiding frame carried by said boom frames and providing a longitudinal guideway for a drilling tool and along which a drilling tool is adjusted to be guided for movement lengthwise of said frame toward and from the work, means for mounting said guiding frame on the remote ends of said boom frames including a connection permitting relative movement between said guiding frame and one of said boom frames during swinging of the latter about its pivot, and adjusting devices connected between said support and said boom frames rei l spectively for swinging said boom frames to elevate said guiding frame from a horizontal position close to the ground to a horizontal position a substantial distance above said base.

16. In a drilling apparatus, the combination comprising a base, a support mounted on said base, a pair of oppositely extending extensible supporting structures carried by said support and projecting laterally from the opposite sides thereof, a horizontal drill guiding frame carried by said supporting structure, means for mounting said guiding frame on the remote ends of said supporting structures including a connection permitting relative motion between said guiding frame and one of said supporting structures during adjustment of the latter, and means for.ex tending said supporting structures to vary their effective lengths,

17. A drilling apparatus as set forth in claim 16 wherein said supporting structures are extendable by fluid under pressure.

18. In a drilling apparatus, the combination comprising a base, a support carried by said base, a pair of oppositely extending boom frames pivotally mounted on said support to swing in vertical planes with respect thereto and projecting laterally from opposite sides of said support, a horizontal cross bar for supporting a vertical drilling tool, means for mounting said cross bar at the outer ends of said boom frames including a connection permitting relative movement between said cross bar and one of said boom frames during swinging of the latter about its pivot, and

power devices connected between said support and said boom frames respectively for swinging said boom frames about their pivots.

19. In a drilling apparatus, the combination comprising a mounting structure, a pair of oppositely extending elongated front and rear boomlike frames pivotally mounted on said mounting structure to swing in vertical planes with respect thereto, one of said boomlike frames being extensible whereby its effective length may be varied, an elongated drill support, means for mounting said drill support at the outer ends of said boomlike frames including connections between said boomlike frames and said drill support at points spaced longitudinally of the latter,

' one of said connections permitting relative bodily movement between said drill support and its associated boomlike frame during swinging of the latter about its pivot, and means for extending said extensible boomlike frame to effect bodily adjustment of said drill support in a longitudinal direction, and said one of said connections permitting such bodily adjustment between said drill support and its associated boomlike frame in a direction longitudinally of said drill support during such longitudinal adjustment of the latter.

20. A drilling apparatus as set forth in claim 19 wherein the front boomlike frame is extensible and said connection which permits such relative bodily movement is between said rear boomlike frame and said drill support and is a sliding connection and has longitudinal sliding engagement with said drill support.

JOHN C. CURTIS.

N 0 references cited. 

